A Study to Evaluate the Safety of Withholding Anticoagulation in Patients With Subsegmental PE Who Have a Negative Serial Bilateral Lower Extremity Ultrasound (SSPE)

This study is currently recruiting participants.
Verified February 2014 by Ottawa Hospital Research Institute
Sponsor:
Information provided by (Responsible Party):
Marc Carrier, MD, Ottawa Hospital Research Institute
ClinicalTrials.gov Identifier:
NCT01455818
First received: October 18, 2011
Last updated: February 26, 2014
Last verified: February 2014
  Purpose

Blood clots in lung arteries (pulmonary embolism) are usually detected using a radiological test called computed tomography (CT scan). As technology advances, the CT scans are able to detect smaller and smaller blood clots. Over time, the frequency of blood clots in the pulmonary arteries has increased significantly (CT scan are now detecting very small blood clots that the investigators could not see before). As a result, more and more people are on blood thinners to treat these small blood clots but their true clinical significance is unknown.

The management of blood thinners is costly and also utilizes scarce healthcare resources. These blood thinners need to be monitored with frequent blood work. Furthermore, every year, approximately 3 percent of patients on blood thinners will have a major bleeding event requiring medical attention.

The investigators don't think that treating these small blood clots in the pulmonary arteries detected on CT scan is worth the risk of bleeding from the blood thinners.

The main goal of this study is to find out if it is safe to not treat very small blood clots in the pulmonary arteries.

The investigators plan to follow 270 patients with small blood clots in their lungs for 90 days. These patients will not be treated with blood thinners but will be followed closely with other non-invasive tests to avoid progression or recurrence of blood clots.


Condition
Subsegmental (Single or Multiple) Pulmonary Embolism

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: A Multicenter Prospective Cohort Management Study to Evaluate the Safety of Withholding Anticoagulation in Patients With Subsegmental PE Who Have a Negative Serial Bilateral Lower Extremity Ultrasound

Resource links provided by NLM:


Further study details as provided by Ottawa Hospital Research Institute:

Primary Outcome Measures:
  • Recurrent VTE [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]
    Recurrent VTE will be diagnosed according to previously published criteria: 1)Lower extremity US revealing non-compressibility at the trifurcation of the popliteal vein or above; OR 2) Venography demonstrating a constant intraluminal filling defect above the trifurcation of the popliteal vein; OR 3) Pulmonary angiography demonstrating a new constant intraluminal filling defect or a cut off of a vessel; OR 4) Ventilation/perfusion scanning with a high probability of PE; OR 5) CTPA demonstrating new intraluminal filling defect in a subsegmental or greater sized pulmonary artery; OR 6) PE discovered at autopsy.


Secondary Outcome Measures:
  • Interobserver agreement for SSPE diagnosis on CTPA (local Vs. central interpretation) [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]
  • Death due to PE [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]
    Definition of death due to PE Certain: hypotension, hypoxia, cardiac arrest with no other explanation other than PE and autopsy or radiographic confirmation Highly probable: criteria for certain but another disease could have caused the death Probable: other cause suspected based on clinical evidence but 100% certainty not available Unlikely: all other cases

  • Death probably due to PE [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]
    Certain: hypotension, hypoxia, cardiac arrest with no other explanation other than PE and autopsy or radiographic confirmation Highly probable: criteria for certain but another disease could have caused the death Probable: other cause suspected based on clinical evidence but 100% certainty not available Unlikely: all other cases

  • Major bleeding [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]

    Major bleeding will be defined according to previously published criteria (51):

    1. Fatal bleeding; OR
    2. Symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intraarticular or pericardial, or intramuscular with compartment syndrome; OR
    3. Bleeding causing a fall in hemoglobin level of 20 g/L (1.24 mmol/L) or more, or leading to transfusion of two or more units of whole blood or red cells

  • Minor bleeding [ Time Frame: 90 day follow-up ] [ Designated as safety issue: Yes ]
    Minor bleeding will be defined as any bleeding not meeting the requirements of a major bleeding event.


Estimated Enrollment: 300
Study Start Date: March 2011
  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Consecutive patients with symptomatic, isolated SSPE* (any number), that are newly diagnosed by computed tomographic pulmonary angiography will be eligible to participate in the study.

Criteria

Inclusion Criteria:

Patients with newly diagnosed isolated SSPE* (any number) that are managed as outpatients will be eligible to participate in the study.

*Isolated SSPE is defined as CTPA demonstrating an intraluminal filling defect in a subsegmental artery with no filling defects visualized at more proximal pulmonary artery levels.

Exclusion Criteria:

  1. Proximal lower extremity (popliteal vein or above) or upper extremity (subclavian vein or above) DVT.
  2. Need for long term oral anticoagulant therapy for reasons other than VTE.
  3. Hospitalized at the time of SSPE diagnosis or admitted to hospital with SSPE diagnosis.
  4. Requiring oxygen therapy to maintain an O2 saturation over 92%
  5. Previous history of DVT or PE
  6. Geographically inaccessible for follow-up
  7. Active Malignancy (defined as other than basal-cell or squamous cell carcinoma of the skin; cancer within the past 6 months; any treatment for cancer in the past 6 months; or recurrent or metastatic cancer)
  8. Pregnancy (or within 6 weeks postpartum)
  9. Have received more than 48 hours of anticoagulants
  10. Unable/refuse to sign informed consent
  11. Asymptomatic SSPE (e.g. SSPE is an incidental finding on a CT scan conducted for reasons other than suspected PE)
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01455818

Contacts
Contact: Kim Danovitch, CCRP 613-737-8899 ext 73667 kdanovitch@ohri.ca
Contact: Amanda Pecarskie, CCRC 613-798-5555 ext 18932 apecarskie@ohri.ca

Locations
Canada, Nova Scotia
Capital District Health Authority Recruiting
Halifax, Nova Scotia, Canada, B3H 1V7
Principal Investigator: Sudeep Shivakumar, MD         
Canada, Ontario
Hamilton General Hospital Recruiting
Hamilton, Ontario, Canada, L8L 2X2
Principal Investigator: Sam Schulman, MD         
London Health Sciences Centre Recruiting
London, Ontario, Canada
Contact: Michael Kovacs, MD MSc         
Principal Investigator: MIchael Kovacs, MD MSc         
Ottawa Hospital Recruiting
Ottawa, Ontario, Canada, K1H 8L6
Contact: Amanda Pecarskie, CCRC    613-737-8899 ext 71065    apecarskie@ohri.ca   
Principal Investigator: Marc Carrier, MD MSc         
Toronto General Hospital Recruiting
Toronto, Ontario, Canada, M5G 2C4
Contact: Erik Yeo, MD       Erik.Yeo@uhn.ca   
Principal Investigator: Erik Yeo, MD         
Canada, Quebec
Sir Mortimer B. Davis Jewish General Hospital Recruiting
Montreal, Quebec, Canada, H3T 1E2
Principal Investigator: Andrew Hirsch, MD         
St. Mary's Hospital Centre Recruiting
Montreal, Quebec, Canada, H3T 1MS
Principal Investigator: Susan Solymoss, MD         
France
Centre Hospitalier Universitaire de Brest Recruiting
Brest, France
Contact: Gregoire Le Gal, MD PhD         
Principal Investigator: Gregoire Le Gal, MD PhD         
Switzerland
Geneva Hospital Recruiting
Geneva, Switzerland
Contact: Marc Righini, MD PhD         
Principal Investigator: Marc Righini, MD PhD         
Sponsors and Collaborators
Ottawa Hospital Research Institute
  More Information

No publications provided

Responsible Party: Marc Carrier, MD, Scientist, Ottawa Hospital Research Institute
ClinicalTrials.gov Identifier: NCT01455818     History of Changes
Other Study ID Numbers: 2009600-01H
Study First Received: October 18, 2011
Last Updated: February 26, 2014
Health Authority: Canada: Ethics Review Committee

Additional relevant MeSH terms:
Embolism
Pulmonary Embolism
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Lung Diseases
Respiratory Tract Diseases

ClinicalTrials.gov processed this record on April 17, 2014